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mri pulse sequences
| Question | Answer |
|---|---|
| Lengthening TR with a short TE in a spin echo sequence will: A. Increase T2 weighting B. Increase T1 weighting C. Increase proton density weighting D. Increase inversion time to null signal from fat | C. Increase proton density weighting |
| In which of the following pulse sequences would you expect to find the shortest TR? A. Fast spin echo B. Inversion recovery C. Gradient echo D. Spin echo | A. Fast spin echo |
| What specifically is a SPGR sequence spoiling? A. The hippocampus B. Longitudinal magnetization C. Transverse magnetization D. Gradient amplitude | C. Transverse magnetization |
| The timing of RF pulses in an MRI pulse sequence controls: A. Resolution capabilities B. Amount of signal in the image C. The time the coil receives the echo D. Image contrast | D. Image contrast |
| In a spin echo sequence, the time between the 90° RF pulse and the 180° RF pulse is known as the: A. TR B. TE C. 1/2 TE D. TI E. Double Echo | C. 1/2 TE |
| In a dual contrast spin echo sequence with echo times of 25ms and 90ms, the second echo image has __________ than the first echo image I. more T2 contrast II. lower signal-to-noise ratio III. more T1 contrast A. I only B. III only C. I & II only | C. I & II only |
| As the TR is increased, I. SNR is increased II. Available number of slices is increased III. T2 information is maximized A. I and II only B. I and III only C. I only D. II only E. I, II and III | A. I and II only |
| Which RF pulse refocuses a decaying spin echo? A. 90° B. 180° C. 67° D. 30° | B. 180° |
| CSF suppression is performed with which type of technique? A. FLAIR B. STIR C. FISP D. SPGR | A. FLAIR |
| In a Fast Spin Echo sequence, the effective TE are the echoes that are encoded: B. In the outer edges of k-space C. With a high amplitude phase encoding gradient D. With a low amplitude phase encoding gradient | D. With a low amplitude phase encoding gradient |
| A STIR sequence with a TI time of 160 ms will null signal from fat at what field strength? A. 0.5 Tesla B. 1 Tesla C. 1.5 Tesla D. 3 Tesla | C. 1.5 Tesla |
| A fast spin echo sequence is faster than a conventional spin echo pulse sequence because: A. Several echoes for each slice are collected during each TR period B. T2* contrast takes less time C. A shorter TR is used for fast spin echo | A. Several echoes for each slice are collected during each TR period |
| Which of the following echo train lengths generates images in the shortest amount of time? A. 3 ETL B. 6 ETL C. 12 ETL D. 16 ETL | D. 16 ETL |
| Which RF pulse is always absent in a gradient echo sequence? A. 90° excitation pulse B. 180° refocusing pulse C. Presaturation pulse D. Flip angle pulse | B. 180° refocusing pulse |
| When performing a gradient echo pulse sequence, what is used to refocus the protons and create the echo? A. A focus group B. Shim coils C. RF coils D. Gradient coils | D. Gradient coils |
| n an inversion recovery sequence, the time interval between the 180° RF pulse and the 90° RF pulse is the: A. TR B. TI C. TE D. 3T | B. TI |
| What is the correct scan time for a spin echo sequence with the following parameters: TR 500 ms, TE 30 ms, matrix 208 x 208, 2 NEX, FOV 200mm? | 3 minutes 28 seconds Scan time --- TR x Phase matrix x NEX = Scan time in milliseconds, ÷ 1000 to calculate scan time in seconds. |
| : A pulse sequence that begins with a 180° RF pulse, followed by a 90° RF excitation pulse, would be a(n): A. Inversion recovery B. Spin echo C. Gradient echo D. Dual echo spin echo | A. Inversion recovery |
| Fast spin echo sequences are fast because: A. The TE used is very short B. More than 1 line of k-space is acquired in each TR period C. No 180º refocusing pulses are used D. The excitation flip angle is very small | B. More than 1 line of k-space is acquired in each TR period |
| Conventional spin echo sequences begin with a __________ RF excitation pulse. A. 25° B. 45° C. 180° D. None of the above | D. None of the above |
| Each train of echoes has what effect on the pulse sequence in a fast spin echo? A. Increases SAR absorption B. Reduces scan time C. Lowers SNR D. All of the above | D. All of the above |
| : In a spin echo pulse sequence, an echo is produced from: A. Flip angle B. A gradient C. A combination of two or more RF pulses D. A 90º RF pulse | C. A combination of two or more RF pulses |
| As the TE is increased, I. The available number of slices is increased II. The available number of slices is decreased III. SNR increases IV. T1 contrast is maximized A. I and III only B. II and III only C. I only D. II only E. I, II, III an | D. II only |
| The fastest sequence commonly and currently available is: A. Fast spin echo B. Inversion recovery C. Echo planar imaging D. Gradient echo | C. Echo planar imaging |
| The gradient that is on during the production of the echo is the: A. Slice select gradient B. Phase encoding gradient C. Frequency encoding gradient D. Inversion recovery gradient | C. Frequency encoding gradient |
| For a given number of slices, which of the following pulse sequences uses the most 180° RF pulses during each TR period? A. Spin echo B. Gradient echo C. Dual contrast spin echo D. Inversion recovery | D. Inversion recovery |
| In a fast spin echo pulse sequence, if the TSE factor (echo train length) is increased by a factor of 3, the scan time will be: A. Twice as fast B. Three times faster C. Six times faster D. Nine times as fast | B. Three times faster |
| The echo time is the A. Time between the 180º inverting pulse and the 90º RF excitation pulse B. Time between the 90º RF pulse and the peak of the signal in the receiver coil C. Time it takes for the flip angle to reach the Ernst angle of peak signa | B. Time between the 90º RF pulse and the peak of the signal in the receiver coil |
| Which of the following sequences is the most insensitive to magnetic field inhomogeneity? A. RF spoiled gradient echo B. Steady state rephased gradient echo C. Echo planar D. Spin echo | B. Steady state rephased gradient echo |
| Which of the following combinations of flip angle (FA) and TR would produce a T2 weighted gradient echo? A. 45 TR; 30º flip angle B. 45 TR; 90º flip angle C. 450 TR; 30º flip angle D. 450 TR; 90º flip angle | C. 450 TR; 30º flip angle |
| In order to produce an echo in a gradient echo pulse sequence, a ___________ is used. A. RF pulse B. Gradient field C. Combination of two RF pulses D. 180° pulse, then 90° pulse E. All of the above F. A & B only | F. A & B only |
| Lengthening TR with a short TE in a spin echo sequence will: A. Increase T2 weighting B. Increase T1 weighting C. Increase proton density weighting D. Increase inversion time to null signal from fat | C. Increase proton density weighting |
| In which of the following pulse sequences would you expect to find the shortest TR? A. Fast spin echo B. Inversion recovery C. Gradient echo D. Spin echo | C. Gradient echo |
| What specifically is a SPGR sequence spoiling? A. The hippocampus B. Longitudinal magnetization C. Transverse magnetization D. Gradient amplitude | C. Transverse magnetization |
| The timing of RF pulses in an MRI pulse sequence controls: A. Resolution capabilities B. Amount of signal in the image C. The time the coil receives the echo D. Image contrast | D. Image contrast |
| In a spin echo sequence, the time between the 90° RF pulse and the 180° RF pulse is known as the: A. TR B. TE C. 1/2 TE D. TI E. Double Echo | C. 1/2 TE |
| In a dual contrast spin echo sequence with echo times of 25ms and 90ms, the second echo image has __________ than the first echo image I. more T2 contrast II. lower signal-to-noise ratio III. more T1 contrast A. I only B. III only C. I & II only | C. I & II only |
| As the TR is increased, I. SNR is increased II. Available number of slices is increased III. T2 information is maximized A. I and II only B. I and III only C. I only D. II only E. I, II and III | A. I and II only |
| Which RF pulse refocuses a decaying spin echo? A. 90° B. 180° C. 67° D. 30° | B. 180° |
| CSF suppression is performed with which type of technique? A. FLAIR B. STIR C. FISP D. SPGR | A. FLAIR |
| In a Fast Spin Echo sequence, the effective TE are the echoes that are encoded: B. In the outer edges of k-space C. With a high amplitude phase encoding gradient D. With a low amplitude phase encoding gradient | D. With a low amplitude phase encoding gradient |
| A STIR sequence with a TI time of 160 ms will null signal from fat at what field strength? A. 0.5 Tesla B. 1 Tesla C. 1.5 Tesla D. 3 Tesla | C. 1.5 Tesla |
| A fast spin echo sequence is faster than a conventional spin echo pulse sequence because: A. Several echoes for each slice are collected during each TR period B. T2* contrast takes less time C. A shorter TR is used for fast spin echo | A. Several echoes for each slice are collected during each TR period |
| Which of the following echo train lengths generates images in the shortest amount of time? A. 3 ETL B. 6 ETL C. 12 ETL D. 16 ETL | D. 16 ETL |
| Which RF pulse is always absent in a gradient echo sequence? A. 90° excitation pulse B. 180° refocusing pulse C. Presaturation pulse D. Flip angle pulse | B. 180° refocusing pulse |
| When performing a gradient echo pulse sequence, what is used to refocus the protons and create the echo? A. A focus group B. Shim coils C. RF coils D. Gradient coils | D. Gradient coils |
| n an inversion recovery sequence, the time interval between the 180° RF pulse and the 90° RF pulse is the: A. TR B. TI C. TE D. 3T | B. TI |
| What is the correct scan time for a spin echo sequence with the following parameters: TR 500 ms, TE 30 ms, matrix 208 x 208, 2 NEX, FOV 200mm? | 3 minutes 28 seconds |
| : A pulse sequence that begins with a 180° RF pulse, followed by a 90° RF excitation pulse, would be a(n): A. Inversion recovery B. Spin echo C. Gradient echo D. Dual echo spin echo | A. Inversion recovery |
| Fast spin echo sequences are fast because: A. The TE used is very short B. More than 1 line of k-space is acquired in each TR period C. No 180º refocusing pulses are used D. The excitation flip angle is very small | B. More than 1 line of k-space is acquired in each TR period |
| Conventional spin echo sequences begin with a __________ RF excitation pulse. A. 25° B. 45° C. 180° D. None of the above | D. None of the above |
| Each train of echoes has what effect on the pulse sequence in a fast spin echo? A. Increases SAR absorption B. Reduces scan time C. Lowers SNR D. All of the above | D. All of the above |
| : In a spin echo pulse sequence, an echo is produced from: A. Flip angle B. A gradient C. A combination of two or more RF pulses D. A 90º RF pulse | D. A 90º RF pulse |
| As the TE is increased, I. The available number of slices is increased II. The available number of slices is decreased III. SNR increases IV. T1 contrast is maximized A. I and III only B. II and III only C. I only D. II only E. I, II, III an | D. II only |
| The fastest sequence commonly and currently available is: A. Fast spin echo B. Inversion recovery C. Echo planar imaging D. Gradient echo | C. Echo planar imaging |
| The gradient that is on during the production of the echo is the: A. Slice select gradient B. Phase encoding gradient C. Frequency encoding gradient D. Inversion recovery gradient | C. Frequency encoding gradient |
| For a given number of slices, which of the following pulse sequences uses the most 180° RF pulses during each TR period? A. Spin echo B. Gradient echo C. Dual contrast spin echo D. Inversion recovery | D. Inversion recovery |
| In a fast spin echo pulse sequence, if the TSE factor (echo train length) is increased by a factor of 3, the scan time will be: A. Twice as fast B. Three times faster C. Six times faster D. Nine times as fast | B. Three times faster |
| The echo time is the A. Time between the 180º inverting pulse and the 90º RF excitation pulse B. Time between the 90º RF pulse and the peak of the signal in the receiver coil C. Time it takes for the flip angle to reach the Ernst angle of peak signa | B. Time between the 90º RF pulse and the peak of the signal in the receiver coil |
| Which of the following sequences is the most insensitive to magnetic field inhomogeneity? A. RF spoiled gradient echo B. Steady state rephased gradient echo C. Echo planar D. Spin echo | B. Steady state rephased gradient echo |
| Which of the following combinations of flip angle (FA) and TR would produce a T2 weighted gradient echo? A. 45 TR; 30º flip angle B. 45 TR; 90º flip angle C. 450 TR; 30º flip angle D. 450 TR; 90º flip angle | C. 450 TR; 30º flip angle |
| In order to produce an echo in a gradient echo pulse sequence, a ___________ is used. A. RF pulse B. Gradient field C. Combination of two RF pulses D. 180° pulse, then 90° pulse E. All of the above | F. A & B only |
| All of the following are types of inversion recovery sequences EXCEPT: A. STIR B. DWI C. FLAIR D. 3D-IR | B. DWI |
| Which of the following echo train lengths generate a set of images with the greatest signal-to-noise, assuming all other parameters are the same? A. 3 ETL B. 6 ETL C. 12 ETL D. 16 ETL | A. 3 ETL |
| The repetition time is the: A. Time between the 180º inverting pulse and the 90º RF excitation pulse B. Time between the 90º RF pulse and the peak of the signal in the receiver coil D. Time between two 90º RF pulses | D. Time between two 90º RF pulses |
Created by:
zach1710